If the rumpus is going to be used as a family day care room, then I think the powder room should be accessible from there. This will make it so much easier for one person to supervise the kids in the room as well as the one who is heading off to the toilet. Perhaps you also need a wet area in there for cleaing up after messy activities. I know someone with a similar family day care set up, and they have toilet and laundry attached to the back of the garage/daycare space. And then the kitchen is adjacent, this makes life a lot easier for the sole person in charge of the kids.

some extra ideas without changes to external walls or windows, removing the ens bath would allow an extra biw and giant shower (although an external door from the ensuite could be great for access to the pool or courtyard) strongly suggest you keep the hallway entry to the powder room for easy access from garage and home office and, adding sliding doors could make the home office more flexible for a future baby's room, the original study divided into garage storage and mudroom, walk in new pantry with sink, replacing the crooked central walls allows for the pantry, extra storage, private access to the minor bedrooms and bathroom and a better location for the heater ...simple refurbishing of the kitchen and ensuite with relatively minor demolition and reconstructing of walls and storage could easily use up $150,000 so probably best to plan and price each area separately but there are extras like the sink in the pantry and handbasin in the family toilet that will improve comfort and be much better value than changing any external doors or windows

I agree with changing the doors from the garage (if not problematic for fire rating), the powder room and the pantry into sliding doors - either cavity or wall mounted for a feature. Also I would definitely have the sink in a bench along the outside wall - and I would have a much bigger window there to let more light into the kitchen. Also swap the opening of the sliding door to the other side and change the door to closer to the kitchen wall so the fridge and bench in the pantry are on the wall furtherest from the kitchen which will give you a longer bench. I would also try to have the doors to the garage and pantry as close as possible to opposite each other for ease of carrying groceries in. Good luck with your build - I hopes it turns out to be everything you are hoping for. <3 :)

@Megan K, I agree I don't follow the Triangle Theory, ie: with galley kitchens this doesn't apply.. Fridge and wall ovens need reachable put down spaces for food stuffs and hot pans. Cooktops need access to a sink for hot liquids.. Many of today's kitchens have more then one sink so that is usually easy to arrange. Fridges need to have easy access for preparing meals, family and even guest access. For me I do what I feel works for me, having said that I'am lucky to be able to work that out where as others need help like what happens on Houzz OKLouise is outstanding for this and has contributed to help many Houzzers over a few years, (who's counting) it takes a lot of time producing floorplans with such consideration and detail..